Warp twisting apparatus



Jan. 13, 1970 w. K. WYATT 3,488,936

WARP TWISTING APPARATUS Filed Nov. 17, 1967 5 Sheets-Sheet l INVENTOR.Wi LLIAM KRK VVYATT ATTORN EYS.

Jan. 13, 197() wl K wYATT 3,488,936

WAR? TWI STING APPARATUS Filed NOV. 17, 1967 5 Sheets-Sheet 2 o o I O oo o o #ed o O o o 09160 /Q 4 FQ.' 5. u 11\IVENTOR.

WILLIAM KIRK WYATT M PFW@ ATTORNEYS.

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Jan. 13, 1970 w. K. WYATT 3,488,936

wma? TwIsTING APP RATus Filed Nov. 17, 1967 5 vA j ets-Sheet 3 LD N lMPM WILL-mm KIRK WYATT BY Jan. 13, 1970 W, K, WYATT 3,488,936

WARP TWISTING APPARATUS Filed Nov. 17, 1967 5 Sheets-Sheet 4 www@ /LclKYB ` INVENTOR.

WILLIAM KIRK WYATT ATTORNEYS.

WARP TWI STING APPARATUS Filed Nov. 17, 1967 5 Sheets-Sheet f' INVENTOR.

WILLIAM KIRK VI/YATT .Y MPM ATTORNEYS.

United States Patent O U.S. Cl. 57-77.4 7 Claims ABSTRACT OF THEDISCLOSURE An apparatus is provided, for machine twisting a plurality ofwarp yarns simultaneously, for providing an initial twisting of yarns.After the initial twist is placed in the yarns, by false twisting pairsof yarns together, the yarns are moved longitudinally through anotherportion of the apparatus, in which yarns in the twist zone are heated toset the filaments in their twisted condition, the twisted yarns thenbeing cooled by a suitable means, and then being separated by passingthe yarns in a twisted pair over opposite sides of a separating pin, toyield a texturized fabric.

BACKGROUND OF THE INVENTION Prior art devices have utilized theprinciple of twisting together pairs of warp yarns, as in a falsetwistingoperation, and then separating the yarns to yield texturized, orbulked yarns. Such prior art devices, for example that disclosed in theU.S. Patent No. 3,091,908 to Carruthers, have proven excellent in theirability to provide quality yarns, particularly those of finer denier.

In general, it has heretofore been thought necessary to alwaysaccomplish the pre-twisting and separation operation as well as allother yarn handling operations, at as high a speed as possible, foreffecting economy of the time required for yarn handling operations.

Such operations generally required drawing yarns from pirns, twistingthe yarns together, either manually or by using a pretwister device suchas that disclosed in the U.S. Patent No. 3,237,391 to Carruthers,heat-setting and separating the twisted yarns, winding the yarns onbobbins or the like, placing the bobbins in a creel, and unwinding thebobbins with the texturized yarns being wound in parallel relation ontoa beam, such as oneA of the tricot type. The yarns were then fed toknitting inachines at the comparatively slow speeds required by knittingmachines.

The prior art has lacked any teaching of using mechanical means forplacing false twist in pluralities of pairs of yarns simultaneously, byother than a hand operation, and furthermore clearly lacks any teachingof false twisting pluralities of groups, or pairs of yarns for directfeed of the yarns to a knitting machine or the like.

SUMMARY OF THE INVENTION The present invention seeks to fulfill a neednot fulfilled by the prior art, in providing an apparatus by whichparallel-disposed yarns rnay be twisted together simultaneously, inpairs, such that all or a substantial nurnber of pairs of yarns across aknitting machine or the like may be twisted in a single operation,thereby eliminating the necessity for twisting yarns by hand, andfurthermore insuring that substantially the same degree of twist ispresent in each pair of yarns, across the machine.

Additionally, the present invention provides an apparatus embodying theabove-mentioned features, which may be operated at suiciently low yarnfed speeds that it can be mounted directly onto a knitting, weavingmachine or the like, and which is capable of handling either fine orheavy denier yarns.

3,488,936 Patented Jan. 13, 1970 ICC Accordingly, it is a primary objectof this invention to provide an apparatus for twisting yarnssimultaneously into a plurality of generally parallel-disposed twistedgroups, each group comprising two or more yarns, as desired.

It is another object of this invention to accomplish the above object,wherein means are provided, carried by the apparatus, for engaging aplurality of groups of yarns, each group comprising a pair of yarns, andapplying false twist to the groups of yarns.

It is a further object of this invention to provide an apparatus forapplying false twists to a plurality of grouped pairs of yarns byengaging the yarns between oppositely moving belt runs.

It is a further object of this invention to accomplish the above object,wherein the yarns are separated into groups simultaneously bytransversely movable members which carry grouping pins or the like.

It is yet another object of this invention to provide a means forsimultaneously applying false twists to pluralities of generallyparallel-disposed pairs of yarns, wherein spacing means are provided formaintaining the yarns in each pair in spaced relation for a portion ofthe twist zone, to facilitate insertion of a separating member betweenthe spaced yarns in each pair, whereby the twist may be removed fromeach pair of yarns, by moving the yarns past separating membersresulting in a plurality of texturized yarns.

It is a further object of this invention to accomplish all of the aboveobjects, wherein the apparatus for applying the false twist to pairs orgroups of yarns is mounted directly on a knitting machine, or the like.

It is a further object of this invention to provide an apparatus forapplying false twists to pairs of yarns and heat-setting the yarns intwisted condition, with the apparatus also including pin means rforseparating the yarns from their twisted condition, the pin means beingVibratory due to the transfer thereto of energy from yarns movingtherepast, wherein the vibratory motion of the pin means facilitates theremoval of snags and the like from the yarns moving therepast.

Other objects and advantages of this invention will be apparent to thoseskilled in the art from the following detailed description, drawings,and appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS FIGURE 1 is a top perspective View ofa knitting Inachine which embodies the yarn twisting apparatus of thisinvention, means for heat-setting the twisted yarn filaments, andseparating pins for separating yarn pairs conveyed longitudinallytherepast.

FIGURE 2 is a top plan view of the yarn twisting belts of thisinvention, wherein grouping means are also illustrated for grouping theyarns into pairs, prior to applying a false twist to each pair of yarns.

FIGURE 3 is a front view of the yarn twisting means illustrated inFIGURE 2, taken generally along the line III-III of FIGURE 2, whereinmeans are illustrated for facilitating relative vertical movement of theupper and lower belt runs which engage and apply false twists to groupedpairs of yarns disposed therebetween.

FIGURE 4 is an enlarged fragmentary top plan view of that portion of theapparatus of this invention which facilitates the grouping of yarns intopairs.

FIGURE 5 is a view generally similar to that of FIG- URE 4, but whereinthe grouping means are illustrated in their respective positions, afterrelative movement, such that the yarns are illustrated as having beendisposed in grouped pairs, after slight transverse movement of the yarnsby means of pins carried by the grouping members.

FIGURE 6 is an enlarged fragmentary top perspective view of a portion ofthe machine of FIGURE 1, wherein there is illustrated a lower twistingbelt, yarn-grouping pin means disposed on opposite sides of the belt, ayarnsetting heater means, a taping block, and twist separating pinsdisposed in a retracted position between the lower twisting belt and thetaping block means.

FIGURE 7 is a view generally similar to that of FIG- URE 6, after yarnshave been grouped into pairs, and wherein the means facilitating thetaping operation and tape cutting is clearly illustrated.

FIGURE 8 is a fragmentary top perspective view of a portion of themachine illustrated in FIGURE 1, wherein the operation of the device ofthis invention is illustrated in a sequence subsequent to thatillustrated in FIGURE 7, and wherein the twisting belts are illustratedin operative relation, for applying a false twist to pairs of yarnsdisposed therebetween, the taping block not being illustrated, in thatit is in a retracted position during the operational stage illustratedin FIGURE 8.

FIGURE 9 is a view generally similar to that of FIG- URE 8, but whereinthe twisting belts and grouping pins are not illustrated, for the sakeof clarity, such apparatus having been retracted following theoperational stage illustrated in FIGURE 8, and wherein the twistseparating pins are illustrated in upper, or operative positions.

FIGURE 10 is a highly enlarged view taken generally along the line X-Xof FIGURE 8, looking downstream of the apparatus of this invention,during the twisting operation illustrated in FIGURE 8.

FIGURE 11 is an enlarged view of a twist separating pin of thisinvention, mounted for angular disposition relative to a vertical plane,the View being taken from one side of the pin, illustrating the mannerin which the pin facilitates the separation of a twisted yarn pair.

FIGURE l2 is a view generally similar to that of FIG- URE 11 but whereinthe separating pin is mounted in vertical disposition, the pin beingdisposed for vibration in the direction of yarn travel, as illustratedby the phantom position of the pin in FIGURE 12.

FIGURE 13 is an enlarged fragmentary top perspective view of a portionof an apparatus generally similar to that of FIGURE 1, but wherein thetwist separating pins are mounted in downward disposition, adjacent tothe twistsetting heating means of this invention, in which position ofthe separating pins the pairs of spaced yarns must be moved rearwardlyfor engaging the pins, following their twisting operation.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawingsin detail, reference is first made to FIGURE 1, wherein there isillustrated a knitting machine generally designated by the numeral 15.

The machine 15 comprises a frame 16 having a front wall 17 and sidewalls 18 and 20. The frame side walls 18 and 20 include respective sidewall mounting extensions 21 and 22.

A sley bar 23 is carried by the mounting extensions 21 and 22 of theframe side walls 18 and 20, at the left-most ends thereof, as viewed inFIGURE 1. The sley bar 23 includes a plurality of upstanding separatorpins 24, for spacing and separating yarns passing therebetween.

A pair of upstream nip rolls 25 and 26 are rotatably carried 'by theframe extensions 21 and 22, peripherally adjacent to each other toprovide a nip therebetween for receiving and carrying yarnstherebetween, longitudinally of the machine 15. The roll 26 includes ashaft extension 27, which extends through the frame extension 21 and hasa sprocket 28 keyed or otherwise secured to the shaft 27; the shaft 27being driven by a suitable motor 30.

A heater 31 is provided, disposed transversely of the machine 15 andcarried between the frame extensions 21 and 22, the heater 31 beingdisposed ust below the paths of yarns extending through the nip of therolls 25 and 26, as viewed in FIGURE 6, and later to be described.

A belt mounting bar 32 is disposed transversely of the machine, betweenthe frame extensions 21 and 22, fixedly secured at opposite ends to theframe extensions 21 and 22. A pair of shafts 33 and 34 are carried bythe bar 32, to one side thereof, as viewed in FIGURE 2, the shaft 33carrying an idler pulley 35, and the shaft 34 carrying a drive pulley36. The pulley 36 is driven through the shaft 34, by means of a motor37. The motor 37 is carried by a bracket 38 which is mounted to the bar32 by suitable bolts 40 which fasten together the bracket 38, the bar30, and a bracket 41 disposed on the opposite side of the bar 32. A belt42 is disposed between the pulleys 35 and 36, being driven by the pulley36.

An upper bar 43 is disposed between the frame extensions 21 and 22,directly above the bar `32, the bar 43 being mounted for pivotalmovement on a bolt 44 disposed between and carried in slots of thebrackets 38 and 41. The right-most end of the bar 43 is provided with auniversal joint 45, in which is carried one end of a threaded member 46.The threaded member 46 is threaded into a pivotal member 47 which ispivotally carried by the right-most end of the bar 32, as viewed inFIGURE 3. The lower end of the threaded member 46 may be provided with asuitable crank turning device or the like, to facilitate the rotation ofthe threaded member 46 and the consequent raising or lowering of the bar43, relative to the bar 32.

The bar 43 is provided with shafts 48 and 50, extending therethrough,and carrying respective idler and drive pulleys 51 and 52.

The shaft 50 is provided with a sprocket 53 which is driven through areversing sprocket 54 by a drive sprocket 55 carried by the shaft 34.The pulleys 51 and 52 carry a belt 56 therebetween. It will be apparentfrom the assembly of the device as illustrated in FIGURE 3, that thebelts 42 and 56 are driven in a same direction such that the lower runof upper belt 56 is oppositely movable relative to the upper run of thelower belt 42. Also, it will be noted that the permissible raising andlowering of the upper bar 43 upon rotation of the threaded member 46will permit the movement of the bars 32 and 43 relative to one another,such that the lower run of the upper belt 56 is movable into closelyadjacent, or touching (if desired) relation to the upper run of thelower belt 42.

Yarn grouping means, generally designated by the numeral 57 areprovided, comprising plate members 58 and 60 disposed on an upstreamside of the lower belt 42, as viewed in FIGURE 6, and a pair of platemembers 61 and 62 disposed on a downstream side of the lower belt 42.The plate members 58, 60, 61 and 62 carry upstanding grouping pins 63,spaced transversely across the machine 15, equidistant from one anotheralong each plate member, the pins 63 being disposed in alignedrelationship, as viewed in FIGURE 6, in one position of the groupingmeans 57. An actuation member 64 is provided, secured to the platemember 58, which, when manually or otherwise actuated, is operative tomove the plate members 58 and 61 transversely of the machine 15, asviewed in FIGURE 7, in such a manner that upstanding pins 63 carried bythe plate members 58 and 61 will engage yarns for movement of the yarnsslightly transversely of the machine 15, to form pairs, in a mannerlater to be described.

A bar 65, is provided, extending transversely of the machine 15, betweenthe frame extension portions 21 and 22 thereof. The bar 65 is carried inslots 68 and 70, for selective vertical movement between operational andretracted positions, upon actuation of a crank handle 72 on one or bothsides of the machine 15, which drives threaded members 74, which arethreaded through the frame extension portions 21 and 22, at both sidesof the machine 15, and into engagement with the bar 65. A plurality oftwist-separating pins 75 are carried by the bar 65 for vertical movementtherewith.

A tape block 76 is provided, mounted between the frame extensionportions 21 and 22, transversely of the machine 15, for verticalmovement within a pair of slots 77 and 78 in the frame extensionportions 21 and 22, generally similar to the movement o'f ythe needlebar 65. A suitable crank 80 and threaded member 81 are provided,suitably connected at one or both ends of the bar 76, through the frameextension portions 21 and 22. The tape block 76 is thus movable betweenoperational and retracted positions in a vertical direction. A pluralityof cutting elements 82 are disposed above the cutting block 76, forvertical movement theretoward. The cutting elements 82 are of the bladetype, and facilitate the cutting of tape, for a purpose later to bedecribed.

A pair of downstream rolls 83 and 84 are provided, rotatably carriedbetween the frame sides 18 and 20, defining therebetween a nip forengagement of and driving yarn ends therethrough. The lower roll 84includes a shaft extension 85, on which is mounted a sprocket 86. Thesprockets `86 and 28 carry a drive chain 87, whereby the lower rolls 84and 26 of the upstream and downstream roll pairs are rotatably driven inthe same direction by the motor 30.

The remaining structure of the knitting machine 15 from the roll 89 onthrough the machine may be conventional, or suited to specific purposes,as desired.

A beam or spool 88 may be mounted on a shaft 9'0, upstream of themachine 15, for supplying yan1 to the machine 15. In the alternative,yarn may be supplied to the machine from a plurality of spindles (notshown) disposed in a creel, if desired.

OPERATION A plurality of yarns Y are provided from a beam 88, and arethreaded through the nip between the rolls 25 and 26, over the heater31, as viewed in FIGURE 6, over the plate members 58 and 60, between theupper and lower belts 56 and 42, respectively, over the plate members 61and 62, above the separator pin bar 65, over the tape block 76, andthrough the nip formed between the rolls 83 and 84, the movement of theyarn ends Y then being arrested.

The actuation portion 64 of the plate member 58 is then movedtransversely of the machine, in a horizontal direction, whereby theplate members 58 and 61 are moved transversely of the machine, thegrouping pins 63 carried by the plate members 58 and 61 engaging theyarns Y1 and Y2 and moving them toward the yarns Y1, and Y4, as viewedin FIGURE 7. It will be understood that alternate yarns disposed betweenin nips of Arolls 25, 26 and 83, 84 across the machine 15 will be movedin a manner of the yarns Y1 and Y2.

The yarns Y1 and Y3, as well as the yarns Y2 and Y.1 are thus grouped inpairs transversely of the machine 15.

Prior to the grouping of the yarns Y1, Y2, Y3 and Y1 a piece of 'tape T1or other adhesive element is placed adhesive side-up on the tape block76. Subsequent to the grouping of the yarns in the aforementionedmanner, another piece of tape T2 is applied across the yarns Y1, Y2, Y3,Y.1 into overlying relation to the piece of tape T1. The cutting blades82 are then moved vertically downwardly, to cut through the tapes T1 andT2, and to separate the tapes into spacer members S1 and S2. Theupstanding pins 79, carried by the tape block 76 maintain the adjacentyarn portions Y1, Y2, Ys and Y1 in` their originally spaced relation,transversely of the machine prior to the application of the tape memberT2.

The cutting blades 82 are then withdrawn upwardly and the tape block 76is moved into a retracted position by engaging the crank handle 80 androtating the threaded member 81 to lower the tape block '76 within theslots 77 and 78. The upper belt 56 is then lowered to the positionillustrated in FIGURE 8, by actuation of lthe threaded member 46.

The belts 56 and 42 are thus brought together, such that adjacent runsare in overlying relation with the yarns Y1 through Y, confinedtherebetween. Upon energizing the motor 37, and rotation of the belts 56and 42, the lower run of the upper belt 56 moves in a direction oppositeto the movement of the upper run of the lower belt 42, thereby providinga twist in each of the groups G1 and G2 of yarns. The twist applied tothe groups G1 and G2 is of the false twist type, known in the art as aS-Z twist. During the application of this twist to the yarn groups G1and G2, the respective spacer members S1 and S2 are freely rotatable,having been separated -by the cutting blades 82. The twist zone will bepresent from the nip of the rolls 25 and 26 to the nip of the rolls 83and 84.

With reference to FIGURE 10, it will be readily apparent that the falsetwist applied to the yarns Y2 and Y1 is effected by frictionalengagement of the yarn surfaces with the surfaces of the oppositelymoving belt runs 42 and 56.

When 'the desired number of twist turns has been placed in the yarns,the motor 37 is de-actuated, the plate members 58 and 61 are returned totheir normal positions illustrated in FIGURE 6, and the threaded member46 is rotated, raising the bar 43 and consequently rai-sing the upeibelt 56 out of engagement with the yarn groups G1 au 2.

The crank handle 72 is then actuated, raising the separator bar 65 inits guide slots 68 and 70 such that the separator pins 75 are raised topass through the voids V1 and V2 between the respective yarns Y1, Y2 andY2, Y4, which are spaced by the respective separator members S1 and S2.

The heater 31 is then operative to heat-set the yarn filaments in theirtwisted condition. The motor 30 is then actuated to drive the rolls 26and 84, to carry the twisted yarn groups G1 and G2 in a downstreamdirection, such that the yarns Y1 and Y3 are separated from their groupG1 as they pass over one of the separator pins 75, and the yarns Y2 andY1 are separated from their group G2 as they pass on opposite sides oftheir separator pln 75. All yarn groups across the machine 15 areseparated in the same manner, and the tape separator members S1 and S2may then be removed, or allowed to pass between the rolls 83 and 84,then to be discarded.

During the continuous heat-setting of the twisted yarn groups G1 and G2,the zone of twist remains constant,

and as a given amount of twist is removed at the downstream end of thetwist zone by yarns passing on opF poslte sides of the yarn separatorpins 75, that same amount of twist yautomatically becomes present at theupstream side of the twist zone, for each group G1 or G2 of yarns, asyarns pass through the nip between the upstream rolls 25 and 26. This isdue to the heat-setting of the twist as yarns are drawn across theheater 31, and the transfer upstream of any rotation to a twisted groupG1 or G2 by a downstream untwisting of the group G1 or G2; suchuntwisting being eiected by passing them over separator pins 75.

With reference to FIGURE l2, it will be observed that the separator pin75 is of a selected size, dimension, and material, such that thefriction of the yarns Y1 and Ya passing thereby, on opposite sides ofthe pin 75 is sufficient to transfer energy to 'the pin 75, tofacilitate a vibration of the pin 75, between the full line positionillustrated in FIGURE 12, and the phantom line position illustratedtherein. All such pins 75`across l'the machine 15 are thus vibrated.This vibration of the pins 75 is elective for eliminating snags betweenthe yarns Y1 and Ys which would tend to retard the separation of theyarns about the pins 75, or which may 'tend to cause breakage of theyarns Y1 and Ya. The resilience of each pin 75, is therefore suicient toallow a moderate bending of each pin 75 to ease the elimination of snagsand the like.

With reference to FIGURE l1, it will also be observed that the pins 75may be mounted in a angular manner, at a slight acute angle with avertical plane, such that the yarns Yl and Y3 may ride upwardly of thepins 75, when a snag engages a pin 75, another feature which eases theelimination of snags and prevents yarn breakage.

It will be observed that in the device illustrated, adjacent pairs ofyarns have been twisted in the same direction. However, it may beadvisable to twist alternate pairs of yarns in opposite directions, inorder to balance forces in the yarns across the knitting machine. .Suchmay be accomplished by first rotating the belts 56 and 42 in onedirection across alternate pairs of yarns and then rotating the belts 56and 42 in another direction across intermediate pairs of yarns. Otherapparatus may also be provided, such as another pair of belts 42 and 56which move in directions opposite to those illustrated in FIGURE 8, andare disposed either above or below those illustrated in FIGURE 8, forapplying twist in an opposite direction to alternate pairs of yarns.

The yarns which pass through the rolls 83 and 84 in a downstreamdirection are texturized, and have high bulk, which enables theaccomplishment of the aforementioned objectives.

With reference to FIGURE 13, it will be observed that an alternativeembodiment of the apparatus of this invention is present, comprising aknitting machine 90 having frame extensions 91 and 92, between which arecarried upstream rolls 93 and 94 and downstream rolls 95 and 96. Aheater 97 is also provided between the frame extensions 91 and 92, asare upper and lower belts 98 and 100, yarn grouping means 101, and atape block 102 and its pin-carrying guide bars 103 and 104, al1 similarto the apparatus of FIGURE 1 of this invention.

In the apparatus of FIGURE 13, however, yarn twist separator pins 105are carried extending vertically downwardly from a carrier bar 106disposed just downstream of the heater 97, but upstream of the twistbelts 98 and 100 for those instances when it is desirable to separatetwisted yarn groups shortly after the yarn filaments are set by the heatfrom the heater 97.

In the embodiment of FIGURE 13, it therefore becomes necessary afterapplying the false twist to the yarns, and prior to separating the yarnsover the pins 105, to manually grasp the separator members S1 and S2 andmove the yarns back upstream to engage the voids V1 and V2 of the groupsof yarns G1 and G2, respectively, over separator pins 105. From thatpoint on, the operation would be continuous, as with the apparatus ofFIGURE 1, differing therefrom in a shorter twist zone only.

It will be apparent that various modifications may be made in thevarious structural details of this invention such as using a coolingzone of the forced air type, or the like just downstream of the heater,should the cooling of heat-set yarns be desirable in specificapplications of this invention, without departing from the spirit andscope of the invention as defined in the appended claims.

In the description above, specific terms have been used for the sake ofclarity, but it is to be understood that this description is directed tothe specific forms of the invention selected for illustration in thedrawings.

What I claim is:

1. An apparatus for twisting yarns comprising means for retaining aplurality of closely spaced yarns in generally parallel disposition,means for separating said yarns into groups, and transversely movablemeans for simultaneously engaging a plurality of said groups of yarnsand applying false twists to said groups of yarns.

2. The apparatus as defined in claim 1 wherein said transversely movablemeans is selectively positionable into and out of engagement with aplurality of said groups of arns. y 3. The apparatus as defined in claim1 wherein said transversely movable means comprises oppositely movablegenerally planar members.

4. The apparatus as defined in claim 3 wherein said members comprisebelt runs.

5. The apparatus as dened in claim 1 wherein said separating meanscomprise guide members disposed upstream and downstream of saidtransversely movable means and being movable into adjacent relation ingroups, with a pair of guide members being provided for each yarn to begrouped with one member of each said pair being disposed on each side ofsaid transversely movable means.

6. The apparatus as defined in claim 1 wherein said separating meansisoperative to separate yarns into groups of two yarns per group.

7. The apparatus as defined in claim 3 wherein said members compriseseparate upper and lower oppositely driven belt runs, at least one saidrun being movable toward the other said run, to dispose said upper runinto generally overlying relation to said lower run.

y References Cited UNITED STATES PATENTS 2,262,589 411/1941 Peck 57-77.4XR 2,908,133 10/1959 Brown 57-77.4 3,045,416 7/1962 Ubbelohde 57-34 XR3,148,520 9/ 1964 Biggers 66-l25 3,154,906 11/1964 Assendelft et al57-34 3,434,275 3/1969 Backer et al 57--156 XR FOREIGN PATENTS 611,45510/1960 Italy.

DONALD E. WATKINS, Primary Examiner U.S. Cl. X.R. 57-51.6; 66-125

